Databases Reference
In-Depth Information
In terms of performance, as we said, RDS is pretty comparable to a large high-memory
EC2 instance with EBS storage and stock MySQL. You can squeeze a little more per-
formance out of the AWS cloud if you use EC2 and EBS directly and install and tweak
a higher-performance version of MySQL, such as Percona Server, but it won't be an
order-of-magnitude difference. With that in mind, it makes sense to base your decision
to use RDS on your business needs, not on performance. If you really need performance
that badly, you should not use the AWS cloud at all.
Other DBaaS Solutions
Amazon RDS isn't the only DBaaS game in town for MySQL users. There are also
services such as FathomDB (
http://fathomdb.com
)
and Xeround (
http://xeround.com
)
.
We don't have enough firsthand experience to recommend any of them, though, be-
cause we haven't had any production deployments on these services. From the limited
public information on FathomDB, it appears to be similar to Amazon RDS, although
it is available on the Rackspace cloud as well as the AWS cloud. It is in private beta at
the time of writing.
Xeround is quite different: it is a distributed cluster of servers, fronted by MySQL with
a proprietary storage engine. It seems to have at least some minor incompatibilities
with or differences from stock MySQL, but it only recently became generally available
(GA), so it's too early to judge it. The storage engine appears to communicate with a
clustered backend system that might bear similarities to NDB Cluster. It has the added
benefit of resharding automatically to add and subtract nodes (dynamic scaling) as the
workload increases and decreases.
There are many other DBaaS services, and new ones are announced pretty frequently.
Anything we write about this will be outdated by the time you read it, so we'll let you
research the landscape yourself.
Summary
There are at least two mainstream ways to use MySQL in the cloud: install it on cloud
servers, or use a DBaaS offering. MySQL runs just fine in cloud hosting, but the limi-
tations of the cloud environment usually result in sharding much earlier than is
necessary outside the cloud. And cloud servers that appear comparable to your existing
physical hardware are likely to provide reduced performance and quality of service.
Sometimes it seems that people are saying, “The cloud is the answer; what is the ques-
tion?” That is one extreme, but people who are fervent believers that the cloud is a silver
bullet are likely to have corresponding problems. Three of the four fundamental re-
sources the database needs (CPU, memory, and disk) can be significantly weaker and/
or less effective in the cloud, and that has a direct impact on MySQL performance.
